Fruit of cherry (Prunus avium L.) and banana (Musa sp.,) AAA Group, Cavendish sub-group cv. Williams Hybrid, when fumigated with ethylene dibromide (EDB) and held at 20°C were injured visibly by treatment concentrations of 32 g/m3 or more. EDB (4 g/m3) stimulated the rates of both ethylene (C2H4) evolution and respiration in cherries, while higher concentrations up to 32 g/m3 caused proportionately greater increases in the rates of gas exchange. Cherries stored at 1° after fumigation with 32 g/m3 EDB did not display the increases in gas exchange which were observed at 20°, but during a 7 day storage period severe Symptoms of phytotoxicity developed. The increases in gas exchange are, therefore, effects and not causes of EDB injury. The Stimulation of C2H4 production in cherries by EDB was reduced by pretreatment with Co2+, indicating that EDB affects the methionine pathway of ethylene synthesis. In bananas treated with 4 g/m3 EDB and held at 20°, the respiration rate increased but C2H4 evolution and electrolyte leakage from slices of pulp tissue were unaffected. When the EDB concentration was raised to 32 g/m3, respiration and C2H4 evolution rates and electrolyte leakage increased.
The endogenous levels of calcium in the cell walls of pericarp tissue of tomato (Lyco-persicon esculentum Mill.) and the soluble and bound calcium content of this tissue were examined during fruit growth and maturation. Cell wall calcium level increased during fruit development to the fully grown, immature stage, but dropped just prior to the onset of ripening. The changes in soluble and bound calcium during ontogeny indicated that calcium was solublized during the early stages of ripening.
Ethylene dibromide (EDB) fumigation of fruit of tomato (Lycopersicon esculentum Mill.) reduced red color development in the outer pericarp, although the inner tissues remained unaffected at EDB doses as high as 35 g/m3. Carotene accumulation was enhanced by EDB at 4 g/m3, but at higher doses the carotene content of the tomato pericarp was reduced. Skin puncture force was reduced in green fruit fumigated at 4 g/m3, but not in breaker or pink fruit; higher skin puncture forces were recorded at higher doses for the three fruit maturities tested, EDB stimulated the respiration of preclimacteric fruit, but fruit fumigated just prior to the climacteric showed a normal respiration peak, although a 4 g/m3 treatment resulted in partial climacteric respiratory rise.
Respiration and ethylene production were determined daily on fruit of A. atemoya Hort. stored at 20°C from preclimacteric to postclimacteric stages. At 5 stages, fruit were analyzed for water, sugars, starch, organic acids, Vitamin C, thiamin, titratable acidity, pH, and total soluble solids. The major changes during ripening were a continuous decrease in starch, a continuous increase in fructose and glucose, an increase in sucrose to a maximum at the climacteric, an increase in malic acid early in the climacteric rise, and a decrease in Vitamin C after the climacteric. Eating quality was optimal 2 days after the climacteric and the levels of protein, fat, dietary fiber, ash, sodium, potassium, iron, calcium, magnesium, zinc, riboflavin, niacin, α-carotene, β-carotene, cryptoxanathin, energy content, and edible portion were determined at this stage. Fruit were stored at temperatures from 0° to 25°. The safe range of storage temperature was between 15° and 25° with 20° being the optimum for the development of eating quality but with 15° giving the longest delay in ripening. Storage at lower temperatures gave rise to symptoms typical of chilling injury.